USB_BANDWIDTH_INFO structure (usbuser.h)
The USB_BANDWIDTH_INFO structure is used with the IOCTL_USB_USER_REQUEST I/O control request to retrieve information about the allocated bandwidth.
Syntax
typedef struct _USB_BANDWIDTH_INFO {
ULONG DeviceCount;
ULONG TotalBusBandwidth;
ULONG Total32secBandwidth;
ULONG AllocedBulkAndControl;
ULONG AllocedIso;
ULONG AllocedInterrupt_1ms;
ULONG AllocedInterrupt_2ms;
ULONG AllocedInterrupt_4ms;
ULONG AllocedInterrupt_8ms;
ULONG AllocedInterrupt_16ms;
ULONG AllocedInterrupt_32ms;
} USB_BANDWIDTH_INFO, *PUSB_BANDWIDTH_INFO;
Members
DeviceCount
The number of devices on the bus.
TotalBusBandwidth
The amount of allocated bandwidth, in bits per millisecond.
Total32secBandwidth
The amount of allocated bandwidth bits in each 32-millisecond time slice.
AllocedBulkAndControl
The amount of bandwidth, in bits per 32-millisecond, that is allocated for bulk and control transfers.
AllocedIso
The amount of bandwidth, in bits per 32-millisecond, that is allocated for isochronous transfers.
AllocedInterrupt_1ms
The amount of bandwidth, in bits per 32-millisecond, that is allocated for interrupt transactions when the period is 1 millisecond.
AllocedInterrupt_2ms
The amount of bandwidth, in bits per 32-millisecond, that is allocated for interrupt transactions when the period is 2 milliseconds.
AllocedInterrupt_4ms
The amount of bandwidth, in bits per 32-millisecond, that is allocated for interrupt transactions when the period is 4 milliseconds.
AllocedInterrupt_8ms
The amount of bandwidth, in bits per 32-millisecond, that is allocated for interrupt transactions when the period is 8 milliseconds.
AllocedInterrupt_16ms
The amount of bandwidth, in bits per 32-millisecond, that is allocated for interrupt transactions when the period is 16 milliseconds.
AllocedInterrupt_32ms
The amount of bandwidth, in bits per 32-millisecond, that is allocated for interrupt transactions when the period is 32 milliseconds.
Remarks
The USB_BANDWIDTH_INFO structure is used with the USBUSER_GET_BANDWIDTH_INFORMATION user-mode request. For a description of this request, see IOCTL_USB_USER_REQUEST.
In Windows 8, this request completes successfully. However, the values retrieved from the underlying USB 3.0 driver stack do not reflect actual information about the allocated bandwidth. That is because the bandwidth information is not exposed by xHCI controllers.
Requirements
| Requirement | Value |
|---|---|
| Header | usbuser.h (include Usbuser.h) |